US threatens Trukey with 'grave consequences' if it prceeds with S-400 deal

"If Turkey takes the S-400s there will be grave consequences,” the Pentagon said Friday, shortly after Turkish Minister of Defense Hulusi Akar said Russia will deliver the first S-400 batteries in October.
Charles Summers, the acting chief Pentagon spokesman, said Washington would refuse to sell Ankara F-35 fighter jets and Patriot surface-to-air missile (SAM) systems as a response.
Back in December, US State Department approved a possible sale of the Patriot missile system to Turkey, a NATO ally, for an estimated total of $3.5 billion. Later in January, a US delegation formally made an offer to Ankara over the sale. Turkish Foreign Minister Mevlüt Çavuşoğlu said earlier this month that the two sides had started negotiating a Patriot deal.
According to the manufacture of F-35 fighter jets, Lockheed Martin, Turkey plans to purchase "100 of the F-35A Conventional Takeoff and Landing variant." The US Congress, however, has so far opposed any possible F-35 sale to Turkey.
As a program partner, Turkish industries "are eligible to become suppliers to the global F-35 fleet for the life of the program,” according to information posted by Lockheed Martin.
Washington claims that Turkey’s acquisition of the Russian missile systems puts in harm's way the F-35 and other US-made weapons and technologies used by the NATO military alliance.
General Curtis Scaparrotti, the Commander of US European Command and NATO Supreme Allied Commander Europe, told Congress earlier this week that he would recommend the US not to follow through with the sale of the F-35 to Turkey if it receives the S-400 missile defense system, .
"I would say first of all if they accept the S-400 and to establish it within Turkey, there's first of all an issue that it's not interoperable with NATO systems nor is it interoperable inside our integrated air defense system so that presents one problem," Scaparrotti said.
"The second has to do with the F-35, it [the S-400] presents a problem to all of our aircraft specifically the F-35, I believe and my best military advice would be that we don't then follow through with the F-35, flying it or working with an ally that's working with Russian systems, particularly air defense systems with one of our what I would say is probably one of our most advanced technological capabilities," he added.
An unnamed US military official had previously told CNN that a major a Turkish S-400 could gather sensitive technical data on the F-35's capabilities and send the critical information to Moscow either intentionally or unintentionally through a possible backdoor in the Russian designed system.
Turkey has repeatedly said that its defense dealings with Russia does not pose any threat to NATO and that it is not on the table to be used as a bargain against F-35 jets and Patriot negotiations.
Turkish President Recep Tayyip Erdoğan also reaffirmed this week that his government will stick to S-400 acquisition plan adding that he might even consider purchasing the more advanced S-500 in the future.